There is a conventional integrated circuit having a power saving mode function. The integrated circuit includes a power-supplied circuit block and a power control circuit block. Power form a source is supplied to the power-supplied circuit block via a transistor. The power control circuit block controls the supply of power to the power-supplied circuit block. After detecting that conditions for shifting into a power saving mode have been satisfied, the power-supplied circuit block notifies the power control circuit block of that fact. After receiving the notification, the power control circuit block turns the transistor OFF (Closing operation) to cut off the supply of power from the power-source power to the power-supplied circuit block. Then, the power control circuit block monitors whether a cut-off cancellation signal is received from outside. If the power control circuit block determines that the cut-off cancellation signal has been received, the power control circuit block turns the transistor ON (Opening operation) to restart the supply of power from the power-source power to the power-supplied circuit block.